Digest for sci.electronics.repair@googlegroups.com - 4 updates in 1 topic

Phil Hobbs <pcdhSpamMeSenseless@electrooptical.net>: Oct 16 01:03PM -0400

>> e.g. plastic or glass. A dab of grease or some tape will make it work a
>> lot better.
 
> I have not experienced that issue, for the record. What I find is that accuracy starts to suffer as the battery gets weak. I view them the same as smoke-alarm batteries - 2x per year, whether I need it or not. And the used batteries are put aside for my increasing number of novelty radios that the grandkids are fighting over. Not in them, but with them for demonstration purposes.
 
Your accuracy requirements aren't high, then. A shiny metal surface can
easily show up as 90% room reflection and 10% surface emission. A bit
of tape will reverse those numbers.
 
Cheers
 
Phil Hobbs
 
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510
 
http://electrooptical.net
https://hobbs-eo.com
"pfjw@aol.com" <peterwieck33@gmail.com>: Oct 16 11:19AM -0700

On Tuesday, October 16, 2018 at 1:03:31 PM UTC-4, Phil Hobbs wrote:
 
> Your accuracy requirements aren't high, then. A shiny metal surface can
> easily show up as 90% room reflection and 10% surface emission. A bit
> of tape will reverse those numbers.
 
Perhaps not. 90% of the use is to verify that I am not looking at a freeze-out on an AHU coil or at the discharge temperature of a chiller. And in such cases, it is pretty much go/no-go. I am not the mechanic, but I have learned over the years that "trust but verify" does not only apply to the former Soviets.
 
But, for 10% of the use, it is to let office workers, docs or other staff know the temperature in their space. The docs have, on more than a few occasions, pulled out a thermometer of their own - and so far, they and my little heat gun have agreed.
 
On rare occasion, I will use it at home to verify radiator temperature against the gauge on the boiler, or to look for hot-spots in some bit of audio or radio equipment, or other. And, if one tube on an output pair is acting differently from another, I understand I have an issue.
 
Peter Wieck
Melrose Park, PA
jurb6006@gmail.com: Oct 16 12:35PM -0700

>"Provided they're really undisturbed. Thermal cycling can cause
delamination problems that don't occur with the oil present. "
 
What I consider the better TO-3s are aluminum, not steel. Another advantage is that they won't bend as much if the mounting surface is not perfectly flat.
 
T
Phil Allison <pallison49@gmail.com>: Oct 16 04:54PM -0700


> What I consider the better TO-3s are aluminum, not steel.
 
** Though once common, Aluminium TO3 paks are no longer used by most manufacturers due to problems with thermal expansion of the aluminium base causing microscopic cracking of silicon chips.
 
Thermal expansion of aluminium is about 7 times greater than that of silicon, limiting the number of full thermal cycles such devices were good for.
 
https://www.engineeringtoolbox.com/thermal-expansion-metals-d_859.html
 
Steel and copper alloy packs are used instead, with most having a "coin" made of a metal with intermediate rate of expansion soldered between the chip and the pak.
 
 
 
> Another advantage is that they won't bend as much if the mounting
> surface is not perfectly flat.
 
** Yuck. Better use only flat heatsinks.
 
 
 
 
.... Phil
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Digest for sci.electronics.repair@googlegroups.com - 2 updates in 1 topic

The Real Bev <bashley101@gmail.com>: Oct 15 04:54PM -0700

On 10/14/2018 11:03 AM, Look165 wrote:
> I got the same problem.
 
> The black plastic is cracked inside ; no sulution except replacement.
 
I don't suppose silicone gasket cement would help... Or would it?
 
 
--
Cheers, Bev
"The object in life is not to be on the side of the
majority, but to be insane in such a useful way that
they can't commit you." -- Mark Edwards
Look165 <look165@numericable.fr>: Oct 16 10:14AM +0200

The leakage comes from the whole body of the Waterpik.
 
For me, it came from the head ("mushroom") of the shower.
 
It is what we call in French "paille" I don't know the exact translation
(straw ? ) in the material of the shower. It is not a problem of gasket
(or o-ring).
 
The cause can be a shock or a fall.
 
 
 
The Real Bev a écrit :
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Digest for sci.electronics.repair@googlegroups.com - 4 updates in 2 topics

jurb6006@gmail.com: Oct 15 01:20AM -0700

Looks like it is bad. It is probably a standard CMOS processor but maybe with a custom program loaded. Maybe not, there is a ROM chip on it, maybe the program is in there.
 
Either way it looks like either calling them, but this thing is a bit old, or finding one in a boneyard. Maybe one got dropped or something. Anyone got one or know where to get one ?
"pfjw@aol.com" <peterwieck33@gmail.com>: Oct 15 05:19AM -0700

> Looks like it is bad. It is probably a standard CMOS processor but maybe with a custom program loaded. Maybe not, there is a ROM chip on it, maybe the program is in there.
 
> Either way it looks like either calling them, but this thing is a bit old, or finding one in a boneyard. Maybe one got dropped or something. Anyone got one or know where to get one ?
 
http://mobilemodding.info/2016/01/fluke-dmm-8600a-repair-photos/
 
An extensive photo-journal of a refurbish. Might help you.
 
Peter Wieck
Melrose Park, PA
The Real Bev <bashley101@gmail.com>: Oct 14 10:32AM -0700

The symptom: the jet doesn't work and water leaks out the bottom.
 
The 5-minute fix: turn the unit over, release the hose going to the
jet, remove the two screws holding the hose to the housing, pull the
hose connection out and replace the o-ring. If you don't have a new
o-ring, move the old one around and put it back together. Temporary, of
course...
 
--
Cheers, Bev
"If you put the government in charge of the desert, there would
be a sand shortage within ten years." -- M. Friedman (?)
Look165 <look165@numericable.fr>: Oct 14 08:03PM +0200

I got the same problem.
 
The black plastic is cracked inside ; no sulution except replacement.
 
Waterpik is rather a good product, but fails with time (5 years max).
 
The Real Bev a écrit :
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